Analytical Performance Evaluation of the QuEChERS-GC-MS Method for the Analysis of Dieldrin in Fillets of Nile Tilapia Oreochromis niloticus

Organochlorine pesticide (OCP) residues act as critical drivers of environmental impacts and pose significant risks to human and animal health. This scenario is further exacerbated by their high environmental persistence, marked bioaccumulative potential, and chronic toxicity. The International Agency for Research on Cancer (IARC) classifies dieldrin, as well as aldrin when metabolized into this substance, as probably carcinogenic to humans (Group 2A). OCPs can accumulate in the fatty tissue of fish. Therefore, when consumed, fish can become a route of human exposure to OCPs, such as dieldrin. A novel method for determining dieldrin in Fillets of Nile tilapia (Oreochromis niloticus) using GC/MS and the original QuEChERS was developed and validated. The optimization of chromatographic parameters resulted in an appropriate retention time (Rt) for dieldrin. Matrix-matched calibration was established to correct the matrix effect (ME) in the quantitative analysis of the pesticide. Dieldrin showed matrix-induced signal suppression of -21.17%. The pesticide studied showed good linearity with a coefficient of determination (R2) of 0.9918. According to the analytical validation standards established by ANVISA, concentrations above the LOQ (50 μg L−1) can be used as a linear working range with high reliability.